Successful individuals are known for sharing similar habits such as waking-up early, saving, providing value to others, and taking calculated risks. But, sometimes the person or the habits aren't 100 percent understood - no matter how much you think you know about them.

Here’s a look at 20 secret facts about billionaires that most of us don’t understand.

1. They’re not fearless.

Every successful billionaire reached that status because they weren’t afraid to put everything on the line and boldly step into the unknown. However, that doesn’t mean that they don’t worry. Having a little bit of pessimism allows you to spot any flaws in your business that you otherwise may have overlooked.

As Bill Gates once said, “In business, by the time you realize you’re in trouble, it’s too late to save yourself. Unless you’re running scared all the time, you’re gone.”

2. They care for their health, not just their wealth.

It’s no secret that taking care of yourself is an essential part of being successful since it reduces stress and prevents you from getting sick all of the time. In other words, if you’re stressed out and battling health concerns all the time -- how can you focus on your business?

But, as Justine Musk, the ex-wife of Elon Musk, explains on Quora, there are a number of other reasons why you should take care of yourself:

“It helps to have superhuman energy and stamina. If you are not blessed with godlike genetics, then make it a point to get into the best shape possible. There will be jet lag, mental fatigue, bouts of hard partying, loneliness, pointless meetings, major setbacks, family drama, issues with the significant other you rarely see, dark nights of the soul, people who bore and annoy you, little sleep, and less sleep than that. Keep your body sharp to keep your mind sharp. It pays off.”

3. They’re comfortable outside the box.

“I believe you have to be willing to be misunderstood if you’re going to innovate,” said Amazon founder Jeff Bezos. What Bezos is talking about is the fact that if all of your ideas were easy to digest, then everyone else would be doing the same exact thing. Successful billionaires have figured out how to take those off-the-wall ideas and connect them to everyday life.

4. Think like a hacker.

Hackers aren’t always those nefarious individuals looking to steal sensitive information for their own gain. As Mark Zuckerberg wrote in a letter to potential Facebook investors, “The Hacker Way" is an approach to building that involves continuous improvement and iteration. Hackers believe that something can always be better, and that nothing is ever complete.”

5. They borrow money before they need it.

This may sound like the most counter-intuitive advice ever, but think it through. It’s more difficult to borrow money when you’re struggling and it helps you build liquidity. Tim Fertitta, who built a restaurant and hospitality empire from a $6,000 loan, explained to CNBC that borrowing money when times are good guarentees you’ll have cash on hand when times are tough.

6. Embrace the crazy.

“When you innovate, you’ve got to be prepared for people telling you that you are nuts," says Larry Ellison. And, that’s not a bad thing. It’s actually an indication that you’re onto something. Again, you’re not going to succeed when everyone is doing the same thing. Adopt and accept different thinking, (think outside the box) and embrace the crazy.

7. They recognize opportunity but don’t have all the answers.

Just because you have a well-thought plan doesn’t mean that it’s going to work. You never know when either disaster or opportunity will strike. As Eric Schmidt, former CEO and current executive chairman of Google said in a commencement address at Carnegie Mellon University in 2009, "it’s all about recognizing opportunity."

“Don’t bother to have a plan at all. All that stuff about planning -- throw that out. It seems to me that it’s all about opportunity and making your own luck. You study the most successful people, and they work hard and they take advantage of opportunities that come that they don’t know are going to happen to them. You cannot plan innovation, you cannot plan invention. All you can do is try very hard to be in the right place and be ready.”

9. Think hard about what can go wrong.

As Michael Simmons writes in an article for Medium, “Until I read billionaire Charlie Munger’s Poor Charlie’s Almanack, I thought the key to success was creating a vision, setting goals, and working hard toward them every day.”

However, Charlie Munger, Berkshire Hathaway vice-chairman and long-time Warren Buffett business partner, argues otherwise and believes in, “thinking through what can go wrong.”

As Munger explains:

“Invert, always invert: Turn a situation or problem upside down. Look at it backward. What happens if all our plans go wrong? Where don’t we want to go, and how do you get there? Instead of looking for success, make a list of how to fail instead — through sloth, envy, resentment, self-pity, entitlement, all the mental habits of self-defeat. Avoid these qualities and you will succeed. Tell me where I’m going to die so I don’t go there.”

10. Investing in yourself is not splurging.

Billionaires are known for being disciplined and frugal. But, there is one exception; investing in yourself and the people around you. Whether it’s purchasing a new computer, going on a vacation, or learning a new skill, investing in yourself can make you more productive and encourages a healthy work-life balance.

As Patrick Soon-Shiong, founder of the biotech startup NantHealth, says, “Invest in yourself and the people you believe in.”

11. They have to make sacrifices.

Along their journey, billionaires had to make some serious sacrifices that aren’t always ideal. Take Nick Woodman the founder of GoPro, for example. "To get GoPro started, I moved back in with my parents and went to work seven days a week, 20 hours a day. I wrote off my personal life to make headway on it."

12. They're comfortable not being the smartest person in the room.

Billionaires are intelligent and skilled, but that doesn’t mean that they have to be the smartest person in the room. In fact, as Michael Dell once said, “Try to never to be the smartest person in the room.”

Instead of being threatened by people who are experts, billionaires thrive on learning from people who are experts so that they can eventually become experts themselves in that area as well.

13. Work with people they already know.

There’s a lot of emphasis on networking. However, instead of cold-calling influencers, prospective clients or investors or networking at parties and events, people like Reid Hoffman have realized that one of the keys to success is by working with your closest allies.

As explained in Fortune, having an ally allows you to regularly consult them when you need advice and “share and collaborate on opportunities together.” There’s a reason why the ‘PayPal Mafia’ has become some of the richest group of people in Silicon Valley.

14. Many had a headstart.

Ben Mezrich, author of "The Accidental Billionaires" and "Bringing Down the House," has said that, "The first trick to becoming a billionaire is being born a millionaire."

While billionaires like Bill Gates and Mark Zuckerberg came from middle-class families, that’s not exactly the same thing as being born into the Walton family. In fact, research has found that 65 percent of billionaires are actually self-made.

16. Billionaires will spend big to influence elections and change public policy.

You’ve probably heard about the millions of dollars that Charles and David Koch poured into elections over the years or how Michael Bloomberg and Mark Zuckerberg tried to persuade Congress to pass comprehensive immigration reform. The fact of the matter is that they weren’t successful since money doesn’t always equate political power.

Billionaires looking to change public policy are usually taken at the state and local level.

17. They delegate.

Billionaires definitely grab the spotlight, but without an amazing team behind them, whether it’s their spouse or employees, they wouldn’t be where they are today.

As Richard Branson has said, “As much as you need a strong personality to build a business from scratch, you also must understand the art of delegation. I have to be good at helping people run the individual businesses, and I have to be willing to step back. The company must be set up so it can continue without me.”

18. They focus on one job.

When you think of billionaires you think that they made their fortune by focusing on just one job. For example, when you think of Warren Buffett you think of him as only an investor. When you think of Steve Jobs you think of the brains behind the iPhone.

The truth is, they’ve worn multiple hats and have juggled numerous responsibilities. As John Catsimatidis, owner, president, chairman, and CEO of Gristedes Foods, once said, “In your company or industry, work every job in that industry. It’s the only way of having a complete understanding of your people and your company.”

19. They stay true to their roots.

We often assume that successful people forget where they came from and head for greener pastures. However, they actually stay true to their roots in order to remain humble. Warren Buffett has remained in Omaha, Nebraska and Amancio Ortega built his billionaire business Zara in his small hometown of La Coruña, Spain.

20. They don’t concentrate on achievements.

Celebrating small victories is one often considered one of the most effective ways to motivate yourself, and your team. However, as Ingvar Krampad, says, “The most dangerous poison is the feeling of achievement. The antidote is to every evening think what can be done better tomorrow.”

Billionaires aren’t complacent, no matter how successful they are. They’re always innovating and looking for the next big thing.

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